In the arteries of human and animal bodies one of the major problems is the loss of strength of the wall of said arteries, which can result in aneurysm formation. An aneurysm may endanger the health of said human or animal because of the risk of internal bleeding which often results in death of the patient. Therefore, aneurysms are usually treated before rupture occurs by vascular protheses which replace the said aneurysmal artery and thus excluding said aneurysm from the circulation.
A new development is the treatment by a so-called endoprosthesis.
Such endoprotheses are well known to the person skilled in the art and can for example be positioned within said artery by means of a number of stents. Although the procedure can be safely performed now, endoleakage is still a major problem immediately following the operation as well as many months following surgery. Endoleakage is the incomplete sealing of the arterial by the endoprosthesis. Endoleakage can result in a pressure build-up within the aneurysmal sac, enclosed between the wall of said artery and the endoprotheses. Monitoring endoleakage is universally performed by visualisation of the endoleakage by means of for example a CT-scan magnetic resonance, duplex ultrasound and the like. Unfortunately, failure to visualise an endoleak does not exclude the presence of such an endoleak. Also without a visible endoleak, the aneurysmal sac can still be under pressure with the danger of ultimate rupture and said internal bleeding. Failure to visualise endoleakage can for example result from failure to introduce sufficient contrast. fluid into said aneurysmal sac, which has been filled with a thrombus. This will mean that either no or a relatively small amount of blood will leak into the aneurysmal sac, resulting in pressure (without flow) to the arterial wall which may result in said rupture. Of course, measuring pressure would be an ideal test to evaluate the absence of an endoleak. However, because of the invase character of pressure measurement, direct pressure measurements can only be obtained during the operation.